What happens if you miss second dose of COVID-19 vaccine; here's what you should do

India, which is considered one of the largest producers of vaccines in the world, is facing a massive shortage of COVID-19 vaccines. Reports from several parts of the country state that numerous vaccination centers have been forced to down their shutters due to lack of supply. One group of individuals who face a unique problem is the ones who have received the first dose but are unable to secure the second.

Currently, only two indigenously produced COVID-19 vaccines are available to the general people—Covaxin (produced by Bharat Biotech) and Covishield (produced by Serum Institute of India). However, a shortage of both vaccines has been reported across the country, with Covaxin face larger scarcity.  So let us take a look at what the outcomes of missing the second dose of the vaccine might be.

Two Jabs for Maximum Protection

The two home-grown vaccines have a slightly different prescribed interval between the two doses. While the interval between the first and second for Covaxin is 28 days, it is four to eight weeks for Covishield.  

According to the latest statement by Bharat Biotech about the interim analysis of Covaxin's phase 3 trials, the vaccine had an efficacy of 78 percent against mild, moderate, and severe COVID-19. The company also claimed that the efficacy against severe COVID-19 was 100 percent. Covishield, on the other hand, is said to have an efficacy of 90 percent. However, in both cases, the said efficacies are after the administration of both doses.

No Immediate Need for Worry

Experts have stressed that both doses of the vaccines are mandatory for maximum protection against the disease. So what happens when one misses the second dose of their vaccine?

There is no cause for immediate worry says noted India virologist Dr. Gagandeep Kang. She told The Print that missing the dose only delays the boosting of the antibodies and does not lead to any significant loss of protection against the virus in the short-term. Most importantly, the repetition of the first dose is not required if the allocated time interval is missed.

"If you get your first dose and don't get your second dose for a couple of years, you probably need to repeat your first dose. If it's a matter of weeks, you definitely don't have to worry. Even if it's a matter of months, you most likely don't have to," said Dr. Kang.

Not All Is Lost

Dr. PK Chandy, senior physician and diabetologist, told Money Control that there are no serious concerns up to two months after missing the second dose. Experts have asserted that a second dose can be delayed till antibodies generated after the first dosage are still present in the body.

Offering advice in this regard, Dr. Chandy said, "If it's after two months, the person can go for an antibody test to confirm whether he has acquired some immunity." He added that if the antibodies are absent, then "it is advisable to go for another full dose."  

Delay Not Advisable

While slightly adjusted timelines can still enable successful inoculation, experts emphasize that delaying the second dose with the pandemic still raging is not advisable. Dr. John Jacob, a virologist, told The New Indian Express that the level of protection offered by both vaccines varies based on the doses received.

He pointed out the while Covishield provides slight protection with the first dose, it increases with the second dosage. However, in Covaxin's case, maximum benefits are acquired only after the second dose, he noted.

"The delay does not make any difference even if a person takes the dose after three or six months. But with the pandemic still playing out, it is better to get the second shot on time as it will save them from the severity of the disease. But once a person crosses 12 months and has not taken the second dose, then she/he needs to start all over again by taking the first dose and then the second one," he explained.